I think I have it too, but it does not bother me at all. Much worse thing is daylily gall midge, especially on early bloomers. I'm seriously thinking of only growing very late daylilies, as they seem to be less affected.

I have observed that many fungi are more spread this year.

I'm just not sure how concerned I am because daylilies in general are kind of falling out of favor with me, but at the same time this stuff is really ugly. I've noticed the infection varies from plant to plant. One plant might not make it at all it looks that bad. Others have it to varying degrees. Some no problems at all, but the vast majority of my plants do have it. I should probably make note of those with seemingly more resistance and make an effort to hang on to them. It really doesn't appear to have affected blooming which is a good thing.

Oh yes, some of my iris have a similar thing going on.

I'm assuming all this is related to 9 inches of rain in May.

Kevin

I don't know if this is the same problem you guys are having. But I live on my grandmothers old homestead and have a huge bed of the old orange ditch lilies.In June they were starting to get some the yellow stripes on their leaves. But within a week the leaves were all dried up and brown. Not a one bloomed this year. I accused my husband of spraying them with round up! LOL But I assume they too have gotten a fungus. So afraid they are gone for good!

April I do not think it is fungus. I think it is weather. I have been growing daylilies for many years. We had the hottest dry weather in history. I had very few blooms on the ditch lilies and the leaves are all brown and dying. Not only the ditch lilies but many of my daylilies. I tried to water but just could not water everyday. They will be back next year.

Kevin,my daylilies have the same thing and it started before heat and drought was an issue. The weather has only served to make things worse. In my case it is the Tarnished Plant Bug. Was able to catch one and was identified as TPB. There seems to be an explosion of these things in Illinois and Iowa. This bug enjoys a diet of over 450 species of plants. In the case of my daylilies it's been devastating. They are very tiny and you won't see them unless you know to what your looking for. Adult TPB's feast on the foliage, There bite is poisonous to the leaves causing damage as you have described. They lay their eggs inside the guard leaf where a lateral or prolif would form killing it. They also suck juices from buds killing those as well.. I'm not saying this your problem just that thats exactly how mine began. Had I not found all this out I would have blamed excessive heat and no rain. One last thing their really fast and fly away as you approach the plants. My mantis and lady bugs are all over the daylilies but I desperately need more predators. I'm working on it. Pat

Anyone wishing information on TP bug. Google tarnish plant bug vegetables or tarnish plant bug agricultural crops. They have more information. AHS does list them as a pest of daylilies. I know not why they're here in such large numbers but they are.

I think I've seen those bugs. I always assumed they were stinkbugs, but maybe I'm getting them confused.

Kevin

I have been asking a similar question over on the daylillie form and getting no help. I considered the issue might be this leaf streak, but I am not convinced. The end result is the same, a lot of yellow dieing fronds but in the beginning I do not see the leaves as you described them. My question is will this kill my lilies or is this a one year quirk and I can rest easy they will return? I have thousands of the double orange daylillies surrounding my property inside and out. I also have a driveway fence lined with various varieties. It is those I am most concerned with returning. The ones lining my property were getting so thick they could use the thinning. On the other form a spray of diluted ammonia was suggested as well as sprinkling comet. This week end I worked on my fence removing all the worst of the dead and yellow leaves and sprayed each plant really well. I use the same mixture of diluted ammonia to kill slugs so was not worried it would hurt the plants. Curiously I found no slugs and I did not see any of the bugs mentioned above. It seems what ever this is is more prone to effect some varieties than others. My stell-o-dora are not effected at all and I have a large yellow variety that is fairing well too. Does it help to clean out the dead/dieing leaves? Does this keep what ever it is from spreading? I am blaming the warm winter. Disease and bugs are killed off by cold cold winters and last year's was just not. Bottom line does any one know if this is a one year anomaly or is this something that will kill the lilies? Is there anything to do to quell the results, and keep it from returning next year?

OT, but I have an "explosion" of box elder bug nymphs. They scurry by the thousands, like something from a horror movie. Good thing they're more or less harmless.

arcy - I think cleaning up the dead stuff can't hurt. I do it just because I'm kind of a tidy person and if you note that blurb I quoted, it says cleaning out the dead stuff helps prevent new infections next year.

I have no idea if this will kill the plants outright - one of mine looks almost gone - but I have noticed the infection seems to have slowed or stopped. It was most noticeable in June when we were getting a lot of rain, but now that it's hot and dry I have seem very little evidence of it spreading. I seem to remember something like this in past years, but not as widespread as this year.

Oh yes, the boxelder babies are out by the billions this year. They are everywhere.

Kevin

Each fall I run the mower over the top of my daylilies so they will get a total clean out then. A few weeks ago or more I sprayed them with ammonia solution and it seemed to stop the spread. I am sure it was just coincidence/timing but I too believe what ever it was is no longer spreading. I did read what you quoted, after I posted. Now we wait and see I guess. I really do not need something new to fight in my gardens!!
I love box elder bugs. My wedding day in October was unusually warm and the side of the church was covered!

In my earlier post here... I was sad about my grandmother's daylilies I have, foliage dying and not blooming this year. Great news! They are growing new foliage now! I was so worried they were goners!